Air intake apparatus for internal combustion engine

ABSTRACT

A housing has an intake passage extending substantially in a vertical direction of a vehicle. A valve is configured to open and dose the intake passage. A shaft supports the valve. A bearing supports the shaft. A hose is connected with an upper side of the housing in the vertical direction and configured to lead intake air into the intake passage. A communication passage configured to communicate an inside of an internal combustion engine of the vehicle with the hose. The communication passage has an opening in the vicinity of a point directly above the bearing. The hose has a wall surface defining a condensate passage, which connects the opening with a target location from which condensate is to be dropped.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 12/272,071, filedNov. 17, 2008, which is in turn based on Japanese Patent Application No.2007-299732 filed on Nov. 19, 2007, the disclosures of each of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an air intake apparatus for an internalcombustion engine.

BACKGROUND OF THE INVENTION

Conventionally, a vehicle such as an automobile is provided with apositive crankcase ventilation device (PCV device) as a blow-by gasreduction device. The PCV device is configured to return blow-by gas(PCV gas) to an air intake system without emitting the PCV gas to theatmosphere, thereby burning the PCV gas in the engine. The blow-by gas(PCV gas) is discharged through a gap between a piston and a cylinder ofan internal combustion engine and emitted from a crankcase. The PCV gasflowing into a crank chamber of the crankcase contains moisture. Whenengine oil (lubricating oil) in the crank chamber is contaminated withthe moisture of PCV gas, the engine oil may be deteriorated. Inaddition, moisture contained in engine oil and PCV gas may evaporate dueto increase in temperature of engine oil accompanied by engineoperation. Consequently, pressure in the crank chamber may increase.Thus, operation of the piston may be disturbed.

The PCV device is configured to draw blow-by gas, which is caused in thecrankcase, and return the blow-by gas into the intake system, therebyburning the returned blow-by gas in the engine. In addition, the PCVdevice is further configured to lead pure fresh air, which is filteredby the air cleaner and removed of impurities, into the crankcase,thereby ventilating the crankcase. The PCV device is, in general,configured to return PCV gas to both an intake passage upstream of anthrottle valve of an electronic throttle device and an intake passagedownstream of the throttle valve so as not draw engine oil. Morespecifically, the PCV device is, for example, configured to return PCVgas to both an intake passage defined in an air cleaner hose (air hose)and an intake passage in the surge tank or an intake manifold. The aircleaner hose connects the air cleaner with the throttle body.

Generally, PCV gas returned to the intake passage upstream of thethrottle valve contains a large amount of moisture or steam.Accordingly, when a PCV hose, a union pipe, or the air hose is cooled,moisture in PCV gas may condense to be condensate. Such condensate dripsfrom an opening of a PCV port into the throttle body, which is locateddownward in the gravity direction. The condensate may infiltrates into agap between a shaft and a bearing, and consequently the condensate maycause freezing (icing).

SUMMARY OF THE INVENTION

In view of the foregoing and other problems, it is an object of thepresent invention to produce an air intake apparatus for an internalcombustion engine, the air intake apparatus configured to restrictinfiltration of condensate into a movable portion around a bearing and ashaft of a valve.

As follows, an electronic throttle device according to a related artwill be described with reference to FIGS. 15 to 18. An air hose 103 isconnected to an upstream end of a throttle body 102 of an electronicthrottle device 101. The air hose 103 is integrally formed with a freshair introduction port (PCV port) 106. The PCV port 106 communicates witha crank chamber with an intake passage 111 through a PCV hose and aunion pipe 104. The crank chamber is located inside of a crankcase of anengine. The intake passage 111 is located upstream of a throttle valve105 in the air hose 103. The vehicle is further provided with theelectronic throttle device 101 having the throttle valve 105, which isconfigured to open and dose an engine intake pipe (throttle bore) so asto control intake air drawn into a combustion chamber of the engine. Theelectronic throttle device 101 includes the throttle body 102, thebutterfly-type throttle valve 105, a shaft 107, a motor, and the like.The throttle body 102 is equipped with a pair of bearings 109, whichslidably supports both axial ends of the shaft 107. The shaft 107 andthe bearings 109 therebetween define a predetermined gap (slidableclearance), thereby the shaft 107 smoothly is rotatable inside thebearing 109. The shaft 107 is rotatable around a center axis shown bythe dotted line in FIG. 17.

Generally, PCV gas returned to the intake passage 111 upstream of thethrottle valve 105 contains a large amount of moisture or steam.Accordingly, when the PCV hose, the union pipe 104, or the air hose 103is cooled, moisture in PCV gas may condense. Consequently, the moisturebecomes condensate in the PCV hose, the union pipe 104, and the PCV port106. Such condensate drips from an opening 110 of the PCV port 106 intothe throttle body 102, which is located downward in the gravitydirection. The condensate may drip to the axial end of the shaft 107 atthe side of the bearing 109 and may infiltrate into the gap between theshaft 107 and the bearing 109. Consequently, the condensate may diffusethroughout the gap by the capillary phenomenon. Thereafter; when theengine is stopped and ambient temperature becomes below the freezingpoint, the condensate infiltrated into the gap between the shaft 107 andthe bearing 109 may freeze. In this case, icing arises at the throttlevalve 105 and the shaft 107, and consequently the throttle valve 105 andthe shaft 107 therebetween cause seizure due to the icing. As a result,the throttle valve 105 may cause a failure (malfunction) such as shaftlock when the engine is again started. Accordingly, it is an object torestrict seizure and shaft lock of the throttle valve 105 caused byicing.

In view of the foregoing problems, so as to avoid icing, it is conceivedto separate the PCV port 106 from the electronic throttle device 101 orto provide the PCV port 106 in the vicinity of a warm water heatingunit, which is configured to heat the throttle body 102 of theelectronic throttle device 101. However, the PCV port 106 may not bearranged apart from the electronic throttle device 101 or may not bearranged in the vicinity of the warm water heating unit, because ofconstraints of layout of component in the vehicle. In particular, whenthe electronic throttle device 101 has a downdraft structure in whichthe intake passage extends in the vertical direction of the vehicle, itis difficult to specifically identify a path of condensate from theintake passage 111 and the PCV port 106. The vertical direction of thevehicle may substantially coincide with the dashed line shown in FIGS.16, 18.

Furthermore, mounting of the electronic throttle device 101 is subjectedwith constraints caused by commonality and downsizing of the engine.Accordingly, the location of the PCV port, through which PCV gasreturns, is further subjected with constraints. In addition, theelectronic throttle devices 101 having the downdraft structure isfurther employed so as to achieve a compact layout. In such a downdraftstructure, condensate freely falls from the opening 110 of the PCV port106, and hence the path of condensate cannot be specifically identified.Accordingly, icing may arise in the gap between the shaft 107 and thebearing 109 due to infiltration of condensate, which drips and fallsfrom the opening 110 of the PCV port 106.

As shown in FIG. 19, in the electronic throttle device 101 having thedowndraft structure, the opening 110 of the PCV port 106 is located atthe directly upper side of the bearing 109, because of constraint oflayout in the vehicle. In the present structure, condensate, which dripsfrom the opening 110 of the PCV port 106, may directly falls onto thebearing 109 of the shaft 107. Consequently, the condensate mayinfiltrate into the gap between the shaft 107 and the bearing 109. Inthis case, icing may arise on the shaft 107, and shaft lock may occur.

Therefore, in the electronic throttle device 101 having the downloadingstructure, it is conceived to determine the distance between the opening110 of the PCV port 106 and the bearing 109 to be equal to or greaterthan 150 mm so as to avoid the direct fall of condensate to the bearing109. Preferably, the opening 110 of the PCV port 106 is provided in theair cleaner. However, when the opening 110 of the PCV port 106 cannot beprovided in the air cleaner, as shown in FIG. 20, the opening 110 of thePCV port 106 may be shifted by 90° from the gap between the shaft 107and the bearing 109 in the direction of the inner circumferentialperiphery of the air hose 103. Further, the opening 110 of the PCV port106 is located on an axis, which passes through a point of a semicircleplate portion of the throttle valve 105. The point of the semicircleplate portion of the throttle valve 105 is most distant from the shaft107 and at the lower side in the gravity direction relative to thecenter axis of the shaft 107 when the throttle valve 105 is in a fulldose position. In the present structure of the electronic throttledevice 101 having the downdraft structure, condensate can be restrictedfrom falling onto the gap between the shaft 107 and the bearing 109.However, the arrangement of the PCV port 106 shown in FIG. 20 becomesincreasingly difficult because of constraints of mounting of componentin the vehicle.

For example, as shown in FIG. 21, JP-A-2003-120245 proposes an airintake apparatus having a downdraft structure. In the present structureof JP-A-2003-120245, the air hose 103 connects the air cleaner with thethrottle body 102, and the air hose 103 is provided with the PCV port106 having an opening 112 upstream of the throttle valve 105 in theintake passage 111. The hose wall surface of the air hose 103 defines anannular step 113 between the opening 112 of the PCV port 106 and thethrottle valve 105 in the throttle body 102. The annular step 113 isinclined with respect to the inner circumferential periphery of the airhose 103. In the present structure of JP-A-2003-120245, condensate isled to a portion of the throttle valve 105, which moves downward whenthe throttle valve 105 opens, and whereby the condensate can berestricted from directly falling onto the bearing 109.

However, in the present air intake apparatus having the downdraftstructure of JP-A-2003-120245, condensate is increased in momentum whenfalling from the opening 112 of the PCV port 106, and the condensate mayovercome the annular step 113. Consequently, the condensate may freelyfall after passing over the annular step 113. In this case, thecondensate cannot be led to the predetermined location, andconsequently, the bearing 109 cannot be steadily protected from directfall of the condensate.

According to one aspect of the present invention, an air intakeapparatus for an internal combustion engine, the air intake apparatuscomprises a housing having an intake passage extending substantially ina vertical direction of a vehicle. The air intake apparatus furthercomprises a valve configured to open and dose the intake passage. Theair intake apparatus further comprises a shaft supporting the valve. Theair intake apparatus further comprises a bearing supporting the shaft.The air intake apparatus further comprises a hose connected with anupper side of the housing in the vertical direction and configured tolead intake air into the intake passage. The air intake apparatusfurther comprises a communication passage configured to communicate aninside of the internal combustion engine with the hose. Thecommunication passage has an opening in the vicinity of a first pointdirectly above the bearing. The hose has a wall surface defining acondensate passage, which connects the opening with a target locationfrom which condensate is to be dropped.

According to another aspect of the present invention, an air intakeapparatus for an internal combustion engine, the air intake apparatuscomprises a housing having an intake passage extending substantially ina vertical direction of a vehicle. The air intake apparatus furthercomprises a valve configured to open and dose the intake passage. Theair intake apparatus further comprises a shaft supporting the valve. Theair intake apparatus further comprises a bearing supporting the shaft.The air intake apparatus further comprises a hose connected with anupper side of the housing in the vertical direction and configured tolead intake air into the intake passage. The air intake apparatusfurther comprises a communication passage configured to communicate aninside of the internal combustion engine with the hose. Thecommunication passage has an opening in the vicinity of a first pointdirectly above the bearing. The opening has a lowest point in a gravitydirection. The lowest point is away from an area in the vicinity of thefirst point.

According to another aspect of the present invention, an air intakeapparatus for an internal combustion engine, the air intake apparatuscomprises a housing having an intake passage extending substantially ina vertical direction of a vehicle. The air intake apparatus furthercomprises a valve configured to open and dose the intake passage. Theair intake apparatus further comprises a shaft supporting the valve. Theair intake apparatus further comprises a bearing supporting the shaft.The air intake apparatus further comprises a hose connected with anupper side of the housing in the vertical direction and configured tolead intake air into the intake passage. The air intake apparatusfurther comprises a communication passage configured to communicate aninside of the internal combustion engine with the hose. Thecommunication passage has an opening in the vicinity of a first pointdirectly above the bearing. The hose has a partition portion. Thepartition portion and a wall surface therebetween define a pocket, whichhas a condensate passage and a drain hole. The condensate passageconnects the opening with a target location, from which condensate is tobe dropped. The drain hole opens at the target location.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription made with reference to the accompanying drawings. In thedrawings:

FIG. 1 is a partially sectional view showing an electronic throttledevice equipped with an air cleaner hose, according to a firstembodiment;

FIG. 2 is a sectional view taken along with the line II-II in FIG. 1,according to the first embodiment;

FIG. 3 is a lateral view showing the electronic throttle device equippedwith the air cleaner hose, according to the first embodiment;

FIG. 4 is an explanatory view showing a state where a bearing isprotected from direct fall of condensate, according to the firstembodiment;

FIG. 5 is a partially sectional view showing an electronic throttledevice equipped with an air cleaner hose, according to a secondembodiment;

FIG. 6 is a lateral view showing the electronic throttle device equippedwith the air cleaner hose and a union pipe, according to the secondembodiment

FIG. 7 is a sectional view taken along with the line VII-VII in FIG. 6,according to the second embodiment

FIG. 8 is a lateral view showing an electronic throttle device equippedwith an air cleaner hose, according to a third embodiment;

FIG. 9 is a side view showing the electronic throttle device equippedwith the air cleaner hose, according to the third embodiment;

FIGS. 10A to 10C are sectional views each being taken along with theline X-X in FIG. 9, according to the third embodiment;

FIGS. 11A, 11B are sectional views each showing a shape of an opening ofa membranous member, according to the third embodiment;

FIG. 12A is a sectional view showing a pocket of an air cleaner hose,and FIG. 12B is a sectional view taken along with the line XIIB-XIIB inFIG. 12A, according to a fourth embodiment;

FIG. 13A is a plan view showing multiple current plates provided in anair cleaner hose, FIG. 13B is a side view showing the air cleaner hose,and FIG. 13C is a sectional view taken along with the line XIIIC-XIIICin FIG. 13B, according to a fifth embodiment;

FIG. 14A is a perspective view showing a bellows tube portion providedin an air cleaner hose, and FIG. 14B is a sectional view taken alongwith the line XIVB-XIVB in FIG. 14A according to a sixth embodiment;

FIG. 15 is a partially sectional lateral view showing an electronicthrottle device equipped with an air cleaner hose, according to arelated art;

FIG. 16 is a lateral view showing the electronic throttle deviceequipped with the air cleaner hose, according to the related art;

FIG. 17 is a partially sectional lateral view showing the electronicthrottle device equipped with the air cleaner hose, according to therelated art;

FIG. 18 is a lateral view showing the electronic throttle deviceequipped with the air cleaner hose, according to the related art;

FIG. 19 is a partially sectional view showing the electronic throttledevice equipped with the air cleaner hose, according to the related art;

FIG. 20A is a plan view showing the electronic throttle device equippedwith the air cleaner hose, and FIG. 20B is a sectional view taken alongwith the line XXB-XXB in FIG. 20A, according to the related art; and

FIG. 21 is a lateral view showing an electronic throttle device equippedwith an air cleaner hose, according to a related art.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(First Embodiment)

(Construction of First Embodiment)

The present first embodiment will be described with reference to FIGS. 1to 4. FIGS. 1 to 3 depict an electronic throttle device equipped with anair cleaner hose. According to the present embodiment, an internalcombustion engine is mounted with an electronic throttle device 1, ablow-by gas reduction device, and the like. The electronic throttledevice 1 is provided with an air cleaner and a downdraft. The engine is,for example, mounted in an engine room of an automobile. In the presentembodiment, the engine is, for example, a water-cooled gasoline engine,which is configured to obtain engine power as thermal energy produced byburning fuel-air mixture in a combustion chamber. The fuel-air mixturecontains intake air, which is filtered by an air cleaner of the engine,and fuel injected from an injector. The engine power is, for example,output shaft torque as engine torque.

The engine further includes an engine cooling device, which has acooling-water circuit through which cooling water is circulated. Theengine cooling device includes a cooling-water circulation path(cooling-water circuit) through which cooling water is circulated forcooling a main body of the engine. The main body of the engine includesa cylinder head, a cylinder block, and the like. The cooling-watercircuit includes a radiator, a thermostat, a water pump, a warm waterheating unit of a throttle body 2, and the like. The engine is, forexample, a water-cooled gasoline engine, which is cooled and controlledat proper temperature by forcedly circulating cooling water through awater jacket of an interior of the engine. Thus, components of theengine are efficiently operable. The engine includes an intake duct(intake pipe) for supplying intake air into each combustion chamber ofeach cylinder of the engine. The engine further includes an exhaust duct(exhaust pipe) to discharge exhaust gas from each combustion chamber tothe outside through a purification device. The air intake duct thereindefines an intake passage for leading fresh air as dean air into thethrottle body 2 of the electronic throttle device 1 through an aircleaner hose (air hose) 7. The fresh air is filtered through the aircleaner. The air intake duct includes an air cleaner case, the aircleaner hose 7 of the throttle body 2, a surge tank, an intake manifold,and the like.

The main body of the engine includes the cylinder head, the cylinderblock, an oil sump, and the like. One side of the cylinder head definesan intake port, which is opened and dosed by a poppet-type intake valve.The other side of the cylinder head defines an exhaust port (not shown)opened and dosed by a poppet-type exhaust valve. The cylinder head isprovided with sparkplugs each having a tip end being exposed to thecombustion chamber of each cylinder. The cylinder head is provided withinjectors (electromagnetic fuel injection valves) each configured toinject fuel into an intake port at an optimum timing. The cylinder blocktherein defines cylinder bores each accommodating a piston. The pistonis connected with a crankshaft via a connecting bar and movable in thevertical direction. The cylinder head and the cylinder block, forexample, therein define a water jacket, which surrounds thecircumference of the cylinder bore. A crankcase is integrally formedwith a lower side of the cylinder block so as to airtightly define theoil sump. The crankcase therein defines a crank chamber. The air cleanerincludes a filtration element (filter element) provided uppermost streamin the air intake duct of the engine. The fitter element is configuredto capture and remove impurities (foreign matters) such as dust and sandcontained in fresh air. The air cleaner hose 7 as an intake pipeconnects an air cleaner with the throttle body 2. The air cleaner hose 7therein defines an intake passage 11 located upstream of a throttlevalve 3. The air cleaner hose 7 will be described later in detail.

According to the present embodiment, the electronic throttle device 1includes the throttle body (housing) 2, a shaft 4, an actuator, and anengine control unit (ECU). The throttle body 2 is airtightly joinedwith, in particular, a downstream end of the air cleaner hose 7 midwaythrough the air intake duct of the engine. The shaft 4 is fixed to thethrottle valve (butterfly valve) 3 so as to support the throttle valve 3for opening and dosing a throttle bore 21, 22 as an inner passage of thethrottle body 2. The actuator as a valve actuating device includes amotor for actuating the throttle valve 3. The engine control unit (ECU)is configured to supply electric power to a coil of the motor accordingto engine operating condition so as to control a throttle position,which corresponds to an angle of the throttle valve 3, in relation tosystems such as an igniter and a fuel injection device.

The electronic throttle device 1 functions as an air intake apparatusfor the engine. The electronic throttle device 1 is configured toactuate the motor according to manipulation of an accelerator pedal by adriver so as to manipulate the throttle position of the throttle valve3. Whereby, the electronic throttle device 1 controls the flow of intakeair, i.e., an amount of intake air supplied to the combustion chamber ofeach engine cylinder, thereby controlling engine speed and engine outputshaft torque. The manipulation of the accelerator corresponds tostepping of the accelerator pedal by the driver. The electronic throttledevice 1 further includes a return spring and a pair of bearings 5, inaddition to the throttle body 2 and the throttle valve 3. The returnspring biases the throttle valve 3 in a dosing direction so as to returnthe throttle valve 3 to a full dose position. The pair of bearings 5supports both ends of the shaft 4 such that the shaft 4 is slidable in arotative direction. In the present embodiment, a coil spring is employedas the return spring. A slide bearing is employed as the first bearing5. A slide bearing, a roller bearing, or a ball bearing is employed asthe second bearing 5. The shaft 4 is rotatable around the center axisshown by the dotted line shown in FIG. 5.

According to the present embodiment, the throttle body 2 is, forexample, formed of aluminum die-casting alloy in a predetermined shape.The throttle body 2 is a housing, which therein holds the throttle valve3. The throttle valve 3 is rotatable from the full dose position to afull open position. The throttle body 2 is screwed to an intake manifoldof the engine using a bolt or the like. In the present embodiment,intake air is filtered through the air cleaner, and the intake air flowsfrom the an inlet portion of the throttle body 2 into the throttle bore21, 22, after passing through the intake passage 11 of the air cleanerhose 7. The intake air is drawn into the intake port of each enginecylinder of each combustion chamber after passing through an intakemanifold, which is connected to an outlet portion of the throttle body2. The inlet portion of the throttle body 2 opens at an upper end in thegravity direction, and the outlet portion of the throttle body 2 opensat a lower end in the gravity direction. The throttle body 2 has acylinder portion (throttle bore wall) 23, which therein defines thethrottle bore 21, 22 substantially in a circular shape in cross section.The throttle body 2, in particular, the cylinder portion 23 isintegrally formed of a metallic material to be in a predeterminedcircular pipe shape, for example. The cylinder portion 23 has an axialend in the axial direction thereof, and the axial end is equipped with asensor cover 24. The sensor cover 24 is configured to support a throttleposition sensor. The sensor cover 24 is, for example, formed of a resinmaterial.

The cylinder portion 23 has a downflow-type throttle bore (intakepassage) 21, 22 extending in the vertical direction of the automobile.The throttle bore 21, 22 extends substantially straight from an inletportion of the throttle body 2 toward an outlet portion of the throttlebody 2. The throttle bore 21, 22 extends in the axial directionsubstantially along both a passage direction of the cylinder portion 23and the vertical direction of the automobile. That is, the throttle bore21, 22 extends substantially perpendicularly to both the rotation centeraxis of the throttle valve 3 and the center axis of the shaft 4. Thevertical direction of the vehicle may substantially coincide with thedashed line shown in FIG. 3. The throttle bore 21 is provided at theupper side in the gravity direction of the throttle body 2, as an intakepassage upstream of the throttle valve 3. The throttle bore 22 isprovided at the lower side in the gravity direction of the throttle body2, as an intake passage downstream of the throttle valve 3. The cylinderportion 23 of the throttle body 2 is provided with the pair of shaftbearings 25, which are opposed to each other via the throttle bore 21,22. Each of the first and second shaft bearings 25 therein defines ashaft accommodating bore, which is substantially in a circular shape incross section. The shaft accommodating bore extends along both thecenter axis of the throttle valve 3 and the center axis of the shaft 4in a shaft direction.

One of the shaft bearings 25 is provided to one end of the shaft 4. Theone of the shaft bearings 25 has the inner circumferential periphery(accommodating bore wall surface) defining the shaft accommodating bore.The accommodating bore wall surface of the one of the shaft bearings 25is fitted with the first bearing 5 such as a slide bearing, whichrotatably supports the one end of the shaft bearings 25. The other ofthe shaft bearings 25 is provided to other end of the shaft 4. The otherof the shaft bearings 25 has the inner circumferential periphery(accommodating bore wall surface) defining the shaft accommodating bore.The accommodating bore wall surface of the other of the shaft bearings25 is fitted with the second bearing 5 such as a slide bearing, whichrotatably supports the other end of the shaft bearings 25. In thepresent structure, the pair of shaft bearings 25 slidably supports theshaft 4 in the rotative direction via the pair of bearings 5. Thecylinder portion 23 of the throttle body 2 has a wall portion, which isintegrally formed with a motor housing 26 for accommodating a motor. Theelectronic throttle device 1 has a block 27, which is substantially in arectangular parallelepiped shape and projected from the cylinder portion23 outward in the radial direction. The block 27 accommodates a warmwater heating unit (warm water passage), which is configured totherethrough lead fluid such as warm water or hot water into thecylinder portion 23 of the throttle body 2 when being used under a coldenvironment such as winter so as to restrict freezing (icing) of thethrottle valve 3. The fluid may be engine cooling water. The block 27 isconnected with an inlet pipe 28 for leading warm water into the warmwater heating unit and an outlet pipe 29 for leading warm water out ofthe warm water heating unit. The inlet pipe 28 and the outlet pipe 29are connected with the cooling-water circulation path (cooling-watercircuit) of the engine cooling device.

In the present embodiment, the throttle valve 3 is provided in thethrottle bore 21, 22 communicated with the combustion chambers and theintake ports of all the cylinders of the engine. The throttle valve 3 isconfigured to open and dose the throttle bore 21, 22. The throttle valve3 is accommodated inside the cylinder portion 23 of the throttle body 2(throttle bore 21, 22) and configured to open and dose the interior ofthe cylinder portion 23. The throttle valve 3 is a rotary-typeintake-air-control valve, which is rotatable relative to the cylinderportion 23 of the throttle body 2. More specifically, the throttle valve3 is a disc-shaped butterfly valve, which is rotatable around the centeraxis of the shaft 4 so as to open and dose the throttle bore 21, 22. Thethrottle valve 3 is rotated, i.e., changed in rotation angle within avalve operation range between the full dose position and the full openposition based on a control signal from the ECU while the engineoperates. The throttle valve 3 is configured to manipulate an openingarea as an intake air passage area of the throttle bore 21, 22 so as tocontrol the flow of intake air. The throttle valve 3 is, for example,returned to the full dose position by being exerted with biasing forceof the return spring or the like when supply of the electric power tothe motor is stopped in response to engine shutdown. Alternatively, inthe present condition, the throttle valve 3 may be operated at a middlelift (intermediate position) where the throttle valve 3 is slightlyopened from the full dose position.

The throttle valve 3 has a disc-shaped portion, which radially extendsoutward in the radial direction from an intersection between the centeraxis of the cylinder portion 23, which extends in the passage directionof the cylinder portion 23 of the throttle body 2, and the center axisof the shaft 4. When the throttle valve 3 is in the full dose position,the back face and the front face of the disc-shaped portion of thethrottle valve 3 is slightly inclined relative to an imaginary line,which is perpendicular to the passage direction of the cylinder portion23 of the throttle body 2 by a predetermined rotation angle in theopening direction. That is, the throttle valve 3 is slightly inclinedrelative to an imaginary line, which is perpendicular to the axialdirection of the throttle bore 21,22 when being in the full doseposition.

According to the present embodiment, the passage direction of thecylinder portion 23 of the throttle body 2 is equivalent to the axialdirection of the throttle bore 21, 22, and the passage direction of thecylinder portion 23 substantially corresponds to the top to bottomdirection (vertical direction) when the electronic throttle device 1 ismounted to the automobile. That is, the passage direction of thecylinder portion 23 substantially corresponds to the vertical directionof the automobile, i.e., the vertical direction with respect to thegravity direction. The disc-shaped portion of the throttle valve 3 isinserted into a valve insertion hole of the shaft 4, and the disc-shapedportion is screwed and fixed to the shaft 4 using a screw or the like.The disc-shaped portion of the throttle valve 3 includes two semicircleplate-like portions as first and second disk portions, which aresegmented by the shaft 4. In the present embodiment, the second discportion is located at the lower side of both the first disc portion andthe shaft 4 with respect to the gravity direction when the throttlevalve 3 is in the full dose position.

The shaft 4 substantially extends straight in the axial directionthereof. The shaft 4 has a center portion as a valve holding portion,which is integrated with the throttle valve 3. The valve holding portionhas the valve insertion hole, which therethrough extends in the radialdirection of the valve holding portion. The shaft 4 is connected withand driven by the output shaft of the motor via an output powertransmission mechanism. The shaft 4 has both the axial ends in the axialdirection, and both the axial ends respectively have two slidingportions (sliding surface), which are respectively supported rotatablyby the pair of shaft bearings 25 and the bearing 5 provided to thecylinder portion 23 of the throttle body 2.

The actuator is an electromotive actuator configured to actuate theshaft 4 of the throttle valve 3 in the opening direction and the dosingdirection. The actuator includes the motor, which is configured togenerate driving force when being supplied with electric power, and theoutput power transmission mechanism, which is for transmitting therotary motion of an output shaft of the motor to the shaft 4. The outputpower transmission mechanism includes a reduction gear mechanism, whichis configured to increase driving force (motor torque) of the motor andreduce the rotation speed of the motor at a predetermined moderatingratio. The reduction gear mechanism includes a pinion gear, anintermediate reduction gear, a final reduction gear, and the like. Thepinion gear as a motor gear is fixed to the output shaft of the motor.The intermediate reduction gear meshes with the motor gear therebyrotated by the motor gear. The final reduction gear meshes with theintermediate reduction gear thereby rotated by the intermediatereduction gear. The output shaft of the motor may be directly coupledwith the shaft 4.

The motor is electrically connected with a battery of the automobile viaa motor drive circuit, which is electronically controlled by the ECU.For example, the motor is configured to generate driving force toactuate the shaft 4 of the throttle valve 3 when a coil of a rotor ofthe motor is supplied with electric power. The ECU controls energizationof the motor so as to control the motor. The ECU has a microcomputerincluding a CPU, a storage unit, an input circuit, an output circuit, apower supply circuit, a timer, and the like. The CPU executes controlprocessings and arithmetic processings. The storage unit is a memorysuch as a ROM and a RAM that stores control programs and control logics.The ECU may be a generally known microcomputer.

The ECU is configured to execute the control programs and control logicsstored in the memory of the microcomputer so as to control energizationof the coil of the motor to manipulate the shaft 4 of the throttle valve3 of the electronic throttle device 1 when an ignition switch (notshown) is turned on (IG-ON). Further, the ECU is configured tomanipulate ignition devices, such as an ignition coil and a sparkplug,and fuel injection devices such as an electric fuel pump and aninjector. In the present structure, control command values as controltarget values of the throttle position, which is relevant to the amountof intake air, the fuel injection quantity, and the like are controlledwhile the engine is operated. When the ignition switch is turned OFF (IGOFF), the engine control, which is performed by the ECU in accordancewith the control program and/or the control logic stored in the memoryof the microcomputer, is forcedly terminated. The engine control mayinclude the throttle position control, the ignition control, the fuelinjection control, and the like.

The ECU is connected with a crank angle sensor, an accelerator positionsensor, a throttle position sensor, and the like. The ECU is furtherconnected with a cooling water temperature sensor, an intake temperaturesensor, an air flow meter, and an intake air pressure sensor. Thevarious sensors respectively output sensor signals, and the outputsensor signals are A/D converted by an A/D converter and transmitted tothe microcomputer of the ECU. These crank angle sensor, the acceleratorposition sensor, the throttle position sensor, the cooling watertemperature sensor, the intake temperature sensor, the air flow meter,and the like configure an operation state detecting unit for detectingan operation state of the engine. The ECU performs a feedback control ofelectric power supplied to the coil of the motor so as to reduce adeviation between the accelerator position signal, which is outputtedfrom the accelerator position sensor, and the throttle position signal,which is outputted from the throttle position sensor.

The blow-by gas reduction device functions as a positive crankcaseventilation device (PCV device). The PCV device is configured to drawblow-by gas, which is emitted into a crank chamber of the crankcase ofthe engine, and return the blow-by gas into an intake system such as asurge tank or an intake manifold of the engine, thereby burning thereturned blow-by gas in the engine. The PCV device is further configuredto lead pure fresh air, which is filtered by the air cleaner and removedof impurities, into the crankcase, thereby ventilating the crankcase.The PCV device includes a fresh air introduction hose and a blow-by gasreflux hose. The fresh air introduction hose connects the engine, inparticular, the crank chamber of the crankcase with the intake passage11 inside the air cleaner hose 7. The blow-by gas reflux hose connectsthe inside of engine, in particular, the inside of a cylinder head coverwith the surge tank or the intake manifold. The PCV hose therein definesa fresh air introduction passage for leading pure fresh air (dean air)filtered by the air cleaner into the engine, in particular, the crankchamber of the crankcase. The blow-by gas reflux hose therein defines ablow-by gas reflux passage for returning blow-by gas (PCV gas), which isemitted from the crank chamber, into the engine intake system such asthe surge tank or the intake manifold. The PCV valve is provided midwaythrough the blow-by gas reflux passage for opening and dosing theblow-by gas reflux passage according to the operation state of theengine.

Next, operations of the air cleaner hose 7 are described with referenceto FIGS. 1 to FIG. 3. The air cleaner hose 7 is formed of an elasticmaterial such as a rubber material or a resin material havingflexibility. The air cleaner hose 7 includes a straight pipe portion 31,a bellows tube portion (accordion portion) 32, a bend portion 33, abellows tube portion (accordion portion) 34, and a straight pipe portion35. The straight pipe portion 31 is airtightly joined with thedownstream end of the air cleaner case. The bellows tube portion(accordion portion) 32 is provided downstream of the straight pipeportion 31. The bend portion 33 is provided downstream of the bellowstube portion 32. The bellows tube portion (accordion portion) 34 isprovided downstream of the bend portion 33. The straight pipe portion 35is provided downstream of the bellows tube portion 34. The straight pipeportion 31 is fitted to the outer circumferential periphery of thedownstream end of the air cleaner case and screwed and fixed to thedownstream end of the air cleaner case by using an air hose band 36. Thebellows tube portion 32, which has multiple bellows peak portions, isprovided between the straight pipe portion 31 and the bend portion 33.The bend portion 33 is substantially circularly bent at a right angle toconnect the bellows tube portion 32 with the bellows tube portion 34.The bellows tube portion 34, which has multiple bellows peak portions,is provided between the bent portion 33 and the straight pipe portion35. The straight pipe portion 35 is fitted to the outer circumferentialperiphery of the upstream end of the throttle valve 3, and the straightpipe portion 35 is screwed and fixed to the upstream end of the throttlevalve 3 by using an air hose band 37.

The air cleaner hose 7 is airtightly joined with the upper end in thegravity direction of the throttle body 2. The air cleaner hose 7 thereindefines the intake passage 11 located upstream of the throttle valve 3.The bend portion 33 of the air cleaner hose 7 is provided with a PCVport 9, which is substantially in a circle shape in cross section. ThePCV port 9 is located at the side of the bellows tube portion 34 andinserted with an union pipe 6. The union pipe 6 is formed of, forexample, a resin material such as thermoplastics. The union pipe 6 maybe formed of poly phenylene sulfide (PPS), polyamide (PA), polypropylene(PP), or polyetherimide (PEI). The union pipe 6 functions as a joint forcoupling one end of the PCV hose of the PCV device with the PCV port 9of the air cleaner hose 7. The union pipe 6 therein defines a fresh airintroduction passage (communication passage) 12, which communicates thefresh air introduction passage in the PCV hose with the intake passage11 inside the air cleaner hose 7. The union pipe 6 includes a smalldiameter portion, a large diameter portion, and a conical cylinderportion. The small diameter portion is located closer to the PCV hose.The large diameter portion is located closer to the PCV port and largerin diameter than the small diameter portion. The conical cylinderportion connects the small diameter portion with the large diameterportion. The small diameter portion of the union pipe 6 functions as aPCV hose fitted portion, which is inserted to the inner circumferentialperiphery of one end of the PCV hose. The large diameter portion of theunion pipe 6 functions as a PCV port fitted portion, which is insertedto the inner circumferential periphery of the PCV port 9.

The PCV port 9 as a fresh air introduction port (communication passage)communicates the engine, in particular, the crank chamber inside thecrankcase with the intake passage 11 upstream of the throttle valve 3inside the air cleaner hose 7 through the PCV pipe and the union pipe 6.The PCV port 9 is defined in a union joint portion 10, which issubstantially in a circular shape and integrally formed with the aircleaner hose 7. The union joint portion 10 extends from the outercircumferential periphery of the air cleaner hose 7 in the tangentialdirection of the air cleaner hose 7. The union joint portion 10 has atip end provided with a union fitted portion 39 to which the largediameter portion of the union pipe 6 is inserted. The PCV port 9 has anopening 13 at the side of a root of the union joint portion 10. Theopening 13 is located in a hose wall surface at least in the vicinity ofan area at the upper side of the bearing 5 with respect to the gravitydirection. Referring to FIG. 1, the union pipe 6 and the PCV port 9 havea condensate passage, which extends substantially straight in thepassage direction of the PCV port 9 from the fresh air introductionpassage 12 to the upstream end (start portion) of a guide groove 14.

According to the present embodiment, the hose wall surface of the aircleaner hose 7 defines the condensate passage. The condensate passageconnects a lowest location, which is in the vicinity of a lowest pointof the opening 13 of the PCV port 9 in the gravity direction, with atarget location (location from which condensate is to be dropped) towhich condensate is to be dropped. The condensate passage is defined bythe guide groove 14, which extends circularly from the lowest locationto the target location, from which condensate is to be dropped, alongthe hose wall surface of the air cleaner hose 7. The lowest location isin the vicinity of the lowest point of the opening 13 of the PCV port 9in the gravity direction. The target location, from which condensate isto be dropped, is at the hose wall surface and in the vicinity of anarea, which is shifted by 90° from the pair of bearings 5 along thecircumferential direction of the inner circumferential periphery of theair cleaner hose 7. In the present embodiment, the target location, fromwhich condensate is to be dropped, i.e., the end portion of the guidegroove 14 is located in one bellows peak portion of the bellows tubeportion 34 of the air cleaner hose 7, when being viewed from the outsideof the air cleaner hose 7. That is, the target location is located inone bellows dip portion of the bellows tube portion 34 when being viewedfrom the inside of the air cleaner hose 7. The target location, fromwhich condensate is to be dropped, may be at the hose wall surface andin the vicinity of a point (first point) directly above the warm waterheating unit, which hearts the throttle body 2, in particular, thecylinder portion 23, using warm water.

In the present embodiment, the second disc portion is located at thelower side of both the first disc portion and the shaft 4 with respectto the gravity direction when the throttle valve 3 is in the full doseposition. Accordingly, when condensate drips to the surface of the firstdisc portion of the throttle valve 3, and when the condensate dropcannot get over the shaft 4, the condensate drop may flow to both axialends of the shaft 4 along the shaft 4. In this case, the condensate dropmay consequently infiltrate into the shaft bearings 25. Therefore, thetarget location, from which condensate is to be dropped, is preferablyat the outer circumferential periphery of the second disc portion of thethrottle valve 3 in the vicinity of the point (third point), which isshifted by 90° from the pair of bearings 5 along the innercircumferential periphery of the air cleaner hose 7. That is, the endportion of the guide groove 14, which corresponds to the targetlocation, is preferably located at the hose wall surface and in thevicinity of an area directly above a position of the outercircumferential periphery of the second disc portion, the position beingmost distant from the center axis of the shaft 4.

(Operation of First Embodiment)

Next, an operation of the electronic throttle device 1 as the intakecontrol device and the PCV device for the internal combustion engineaccording to the present embodiment is briefly described with referenceto FIGS. 1 to 3. When the ignition switch is turned on, e.g., theignition key switch is turned on (IG-ON), the ECU starts control ofenergization of the motor of the throttle valve 3 and the like of theelectronic throttle device 1. In addition, the ECU further actuates theignition device, such as the ignition coil and the sparkplug, and thefuel injection device, such as the electric fuel pump and the injector.Thus, the engine is operated. In the present condition, the ECU inputsthe accelerator position signal, which is outputted from the acceleratorposition sensor and changed in accordance with depression of theaccelerator pedal by the driver. The ECU supplies electric power to themotor so as to rotate the output shaft of the motor, thereby controllingthe throttle valve 3 at a predetermined throttle position correspondingto a predetermined rotation angle. Thus, the shaft 4, which is connectedwith the output shaft of the motor, is rotated against biasing force ofthe return spring by a rotation angle corresponding to the depression(accelerator manipulation) of the accelerator pedal. Thus, the shaft 4rotates, thereby the throttle valve 3, which is supported by the shaft4, is actuated in the opening direction from the full dose positiontoward the full open position.

When a specific cylinder of the engine starts an intake strokesubsequent to an exhaust stroke, an intake valve opens and the specificpiston downwardly moves in the specific cylinder. In the presentcondition, pressure in the combustion chamber of the cylinder furtherdecreases further less than atmospheric pressure according to downwardmovement of the piston, thereby fuel-air mixture is drawn from theopening intake port into the combustion chamber. In the presentcondition, the throttle body 2 opens the throttle bore 21, 22, which islocated midway through the air intake duct, according to the valve anglecorresponding to the throttle position of the electronic throttle device1. Thus, engine speed is changed corresponding to the depression(accelerator manipulation) of the accelerator pedal.

At the time of a partial-load operation, such as an idling operation,the throttle position of the electronic throttle device 1 is relativelysmall. In such a partial-load operation, negative pressure occurs in thethrottle bore 22 downstream the throttle valve 3 in the intake passage.In the present condition, when the PCV valve of the PCV device opens,PCV gas is drawn by negative pressure from the crank chamber of thecrankcase inside the engine into the intake passage downstream of thethrottle valve 3. Accordingly, air flows in the fresh air introductionpassage and the blow-by gas reflux passage toward the surge tank or theintake manifold.

More specifically, dean air, which is filtered through the air cleaner,flows from the PCV port 9 of the air cleaner hose 7 into the crankchamber of the crankcase after passing through the fresh airintroduction passage. Whereby, the crank chamber is ventilated. Further,PCV gas and dean air flow into the intake passage downstream of thethrottle valve 3 after passing through the blow-by gas reflux passage.In the present operation, PCV gas, which is emitted in the crankchamber, is returned into the intake passage downstream of the throttlevalve 3 and led into the combustion chamber of each engine cylinder,thereby re-combusted. Thus, engine oil can be restricted fromdeterioration, and increase in internal pressure in the crank chambercan be suppressed. Whereby, operation of the piston can be maintained.On the other hand, when the throttle position of the electronic throttledevice 1 is at maximum in the condition where the throttle valve 3 is inthe full open position, negative pressure becomes significantly small inthe intake passage downstream of the throttle valve 3. Alternatively,pressure in the intake passage downstream of the throttle valve 3becomes substantially the same as the atmospheric pressure. In thepresent condition, even when the PCV valve opens, PCV gas, which isexerted with negative pressure, cannot be sufficiently returned into theintake passage downstream of the throttle valve 3 through the blow-bygas reflux passage. Otherwise, when the throttle valve 3 is in the fullopen position, intake air flow through the intake passage 11 in the aircleaner hose 7 and the throttle bore 21, 22 in the throttle body 2becomes maximum. In the present condition, PCV gas, which is emitted inthe crank chamber, is entrained in the intake air flow through theintake passage 11 and introduced from the opening 13 of the PCV port 9to the intake passage 11 upstream of the throttle valve 3 through thefresh air introduction passage. Thus, together with intake air, PCV gasflows from the intake passage 11 upstream of the throttle valve 3 intothe intake passage downstream of the throttle valve 3.

(Effect of First Embodiment)

According to the present embodiment, the guide groove (condensatepassage) 14 is located in the hose wall surface of the air cleaner hose7 at the directly upper side of the throttle body 2 of the electronicthrottle device 1 including the downdraft. The condensate passageconnects the lowest location, which is in the vicinity of the lowestpoint of the opening 13 of the PCV port 9 in the gravity direction, withthe target location from which condensate is to be dropped. The guidegroove 14 extends circularly from the lowest location, which is in thevicinity of the lowest point of the opening 13 of the PCV port 9 in thegravity direction, to the target location, from which condensate is tobe dropped. The target location is in the vicinity of the point (thirdpoint), which is shifted by 90° from the bearing 5 along the innercircumferential periphery of the air cleaner hose 7.

In the present structure, even when condensate flows out of the opening13 of the PCV port 9, the condensate can be released to the location inthe vicinity of the point, which is shifted by 90° from the bearing 5 inthe direction of the inner circumferential periphery of the air cleanerhose 7. Thus, condensate flowing out of the opening 13 of the PCV port 9is induced to the target location from which condensate is to bedropped, (location to be dropped with condensate), by the guide groove14 provided in the hose wall surface of the air cleaner hose 7.Thereafter, the condensate drips into the target location. The targetlocation may be distant from the directly upper side of the bearing 5,for example. Therefore, even in the electronic throttle device 1 havingthe downdraft structure in which the PCV port 9 opens in the vicinity ofthe directly upper side of the bearing 5, condensate flowing out of theopening 13 of the PCV port 9 can be restricted from directly drippinginto the bearing 5. In the present structure, the bearing 5 can beprotected from direct fall of condensate, and hence the bearing 5 andthe gap between the sliding surface of the bearing 5 and the shaft 4 ofthe throttle valve 3 can be protected from permeation of condensate.

Further, the target location, from which condensate is to be dropped,i.e., the end portion of the guide groove 14 is preferably near thepoint, which is shifted by 90° from the bearing 5 in the direction ofthe inner circumferential periphery of the air cleaner hose 7. That is,the target location is preferably distant from the center axis of theshaft 4 and at the outer circumferential periphery of the second discportion of the throttle valve 3. The condensate flows into the throttlebore 22 located downstream of the throttle valve 3, i.e., lower side ofthe throttle valve 3, in response to opening of the throttle valve 3.

In the present operation, condensate, which flows out of the opening 13of the PCV port 9, is released to the target location, from whichcondensate is to be dropped. Therefore, the bearing 5 and the gapbetween the wall surface defining the bearing hole of the bearing 5 andthe sliding surface of the shaft 4 of the throttle valve 3 can beprotected from permeation of condensate. Thus, the throttle valve 3 andthe shaft 4 can be protected from causing icing. Further, seizure,failure, i.e., malfunction, and shaft lock due to icing of the throttlevalve 3 and the shaft 4 can be steadily restricted.

(Second Embodiment)

The present second embodiment will be described with reference to FIGS.5 to 7. FIG. 5 shows an electronic throttle device equipped with an aircleaner hose according to the present second embodiment. FIGS. 6, 7 showthe air cleaner hose and a union pipe according to the present secondembodiment. Referring to FIG. 5, in the present embodiment, the unionpipe 6 and the PCV port 9 have the condensate passage, which extendssubstantially straight in the passage direction of the PCV port 9 fromthe fresh air introduction passage 12 to the upstream end (startportion) of the guide groove 14. In the present embodiment, the passagedirection of the PCV port 9 is substantially in parallel with the axialdirection of the shaft 4 of the throttle valve 3. In addition, accordingto the present embodiment, the air cleaner hose 7 is not provided withthe bellows tube portion 34, and the bend portion 33 is directlyconnected with the straight pipe portion 35. The hose wall surface ofthe air cleaner hose 7 extends from the bend portion 33 to the straightpipe portion 35 and defines the condensate passage. The condensatepassage connects the lowest location, which is in the vicinity of alowest point of the opening 13 of the PCV port 9 in the gravitydirection, with the target location from which condensate is to bedropped.

The condensate passage is defined by the guide groove 14, which extendscircularly from the lowest location to the target location, from whichcondensate is aimed to be dropped, along the hose wall surface of theair cleaner hose 7. The lowest location is in the vicinity of the lowestpoint of the opening 13 of the PCV port 9 in the gravity direction. Thetarget location, from which condensate is aimed to be dropped, is at thehose wall surface and in the vicinity of an area, which is shifted by90° from the pair of bearings 5 along the circumferential direction ofthe inner circumferential periphery of the air cleaner hose 7. Thetarget location, from which condensate is aimed to be dropped, may be atthe hose wall surface and in the vicinity of a point (second point)directly above the warm water heating unit, which hearts the throttlebody 2, in particular, the cylinder portion 23, using warm water. Asdescribed above, the electronic throttle device 1 having the downdraftstructure according to the present embodiment is capable of produce aneffect similarly to the first embodiment.

(Third Embodiment)

The present third embodiment will be described with reference to FIGS. 8to 11B. FIGS. 8, 9 depict an electronic throttle device equipped with anair cleaner hose. In the electronic throttle device 1 having thedowndraft structure according to the present embodiment, the straightpipe portion 35 of the air cleaner hose 7 is airtightly joined with theupper end of the throttle body 2 in the gravity direction. That is, thestraight pipe portion 35 of the air cleaner hose 7 is airtightly joinedwith the upper portion of the throttle body 2 in the vertical direction.

As shown in FIG. 10C, the opening 13 of the PCV port 9 is, in general,substantially in a circular shape in cross section. In the presentstructure, condensate, which reaches the opening 13 of the PCV port 9,drips and falls from the lowest point X of the opening 13 in the gravitydirection. The lowest point X substantially coincides with the center ofthe opening 13 depicted by the dashed line in FIG. 10C. Accordingly, ina structure in which the opening 13 of the PCV port 9 opens directlyabove the bearing 5, condensate may drip from the lowest point X of theopening 13 in the gravity direction and may directly fall onto thebearing 5. In this case, the condensate may infiltrate into the bearing5 and the gap between the hole wall face of the bearing hole of thebearing 5 and the sliding surface of the shaft 4 of the throttle valve3.

Therefore, according to the present embodiment, as shown in FIG. 10A,the opening 13 of the PCV port 9 is substantially in an oval shape incross section. Alternatively, according to the present embodiment, asshown in FIG. 10B, the opening 13 of the PCV port 9 may be substantiallyin a parallelogram in cross section. As described above, the crosssection of the opening 13 of the PCV port 9 may be determined to be anon-circle shape (irregular hole shape) such as an ellipse form, aparallelogram, or the like. Thus, the lowest point of the opening 13 inthe gravity direction can be displaced and whereby the lowest point ofthe opening 13, from which condensate falls, can be shifted from thepoint X, which is depicted by the dashed lines in FIGS. 10A, 10B, to thepoint Y. In the present structure, the target location, from whichcondensate is to be dropped, can be shifted, i.e., displaced from thepoint directly above the bearing 5. That is, the lowest point in theopening 13 of the PCV port 9 in the gravity direction can be determinedaway from the point directly above the bearing 5. Therefore, condensatecomes to drip and fall from the lowest point of the opening 13 of thePCV port 9 in the gravity direction, the lowest point being away fromthe area around the point directly above the bearing 5. As describedabove, the electronic throttle device 1 having the downdraft structureaccording to the present embodiment is capable of produce an effectsimilarly to the first embodiment.

In addition, as shown in FIG. 11A, membranous member 15 may be providedto the opening of the PCV port 9 in the present embodiment. Themembranous member 15 is configured to throttle the cross-sectional areaof the opening of the PCV port 9. The membranous member 15 partiallysurrounds the opening of the PCV port 9 and has a through hole 41, whichis substantially in a circular shape and extends in the thicknessdirection of the membranous member 15. That is, the through hole 41extends in the passage direction of the PCV port 9. The membranousmember 15 has a condensate drain groove 42, which protrudes downward inthe gravity direction from the through hole 41.

The condensate drain groove 42 extends from an opening edge of thethrough hole 41 in the tangential direction of the through hole 41substantially downward in the gravity direction. The lower end of thecondensate drain groove 42 in the gravity direction defines the lowestpoint of the through hole 41 in the gravity direction. The lowest pointof the through hole 41 in the gravity direction is away from an area inthe vicinity of a point directly above the bearing 5. In the presentstructure, condensate, which reaches the opening of the PCV port 9, isonce dammed, i.e., blocked by the membranous member 15. The condensate,which likely overflows from the through hole 41, drips and falls fromthe condensate drain groove 42. That is, condensate drips and falls fromthe location away from the area directly above the bearing 5, i.e.,shifted from the lowest point of the through hole 41 in the gravitydirection.

Alternatively, as shown in FIG. 11B, a membranous member 16 may beprovided to the opening of the PCV port 9 in the present embodiment. Themembranous member 16 is configured to throttle the cross-sectional areaof the opening of the PCV port 9. The membranous member 16 partiallysurrounds the opening of the PCV port 9 and has a through hole 43, whichis substantially in a circular shape and extends in the thicknessdirection of the membranous member 16. That is, the through hole 41extends in the passage direction of the PCV port 9. The through hole 43has the center shifted eccentricity leftward in FIG. 11B from both thecenter of the opening of the PCV port 9 and the center of the membranousmember 16, which are depicted by the dashed line in FIG. 11B.

As described above, the membranous member 15, 16 is provided to theopening of the PCV port 9, and whereby the lowest point of the openingin the gravity direction can be displaced, i.e., shifted. Thus, thelowest point of the opening, from which condensate falls, can be shiftedfrom the point X to the point Y. In the present structure, the targetlocation, from which condensate is to be dropped, can be shifted, i.e.,displaced from the point directly above the bearing 5. That is, thelowest point in the through hole 41, 43 of the membranous member 15, 16in the gravity direction can be determined away from the point directlyabove the bearing 5. Therefore, condensate comes to drip and fall fromthe lowest point of the through hole 41, 43 of the membranous member 15,16 in the gravity direction, the lowest point being away from the areaaround the point directly above the bearing 5. As described above, theelectronic throttle device 1 having the downdraft structure according tothe present embodiment is capable of produce an effect similarly to thefirst embodiment.

Further, according to the present embodiment, the throttle valve 3 andthe shaft 4 can be further protected from icing without providing aguide portion to the hose wall surface of the air cleaner hose 7. Thatis, the hose wall surface of the air cleaner hose 7 need not be providedwith, for example, a guide recessed portion dented toward the outside ofthe air cleaner hose 7 or a guide projected portion projected toward theinside of the air cleaner hose 7. Therefore, intake air flow through theintake passage 11 upstream of the throttle valve 3 in the air cleanerhose 7 can be restricted from disturbance caused by the additional guideportion such as the guide recessed portion and the guide projectedportion. For example, disorder of intake air flow through the aircleaner hose 7 can be reduced, and therefore pressure loss in intake airflow through the air cleaner hose 7 can be suppressed.

(Fourth Embodiment)

FIGS. 12A, 12B show a pocket provided to an air cleaner hose accordingto the present fourth embodiment. According to the present embodiment,the opening 13 of the PCV port 9 is located in the vicinity of the pointdirectly above the bearing 5 in the air cleaner hose 7. A partitionportion 51 is integrally formed with the hose wall surface of the aircleaner hose 7. The partition portion 51 has an opposed portion 52,which is opposed to the opening 13 of the PCV port 9 at a predeterminedgap. The partition portion 51 is defined by a partition plate 53, whichis substantially in an arc shape and extends from the opposed portion 52to the target location, from which condensate is to aimed be dropped,along the hose wall surface of the air cleaner hose 7.

A pocket 17 is defined by an outer wall as the straight pipe portion 35of the air cleaner hose 7 and an inner wall as the partition plate 53,which is opposed to the hose wall surface of the air cleaner hose 7. Thepocket 17 is further defined by a bottom wall 54 as a lower portion thepartition portion 51 in the gravity direction and sidewalls as both sideportions 55, 56 of the partition portion 51 in the circumferentialdirection. In the present structure, the partition portion 51 definesthe pocket 17 with the hose wall surface of the air cleaner hose 7 fortemporarily accumulate condensate, which flows out from the opening 13of the PCV port 9. That is, the partition portion 51 and the hose wallsurface of the air cleaner hose 7 therebetween define the pocket 17. Thepocket 17 has an upper surface in the gravity direction, and the uppersurface opens. The pocket 17 has a lower surface in the gravitydirection, and the lower surface is at the lower side from a lowestpoint of the opening 13 of the PCV port 9 in the gravity direction by apredetermined depth.

The pocket therein defines the condensate passage. The condensatepassage connects the lowest location, which is in the vicinity of thelowest point of the opening 13 of the PCV port 9 in the gravitydirection, with the target location from which condensate is aimed to bedropped. The lower surface of the pocket 17 in the gravity direction,i.e., the bottom wall 54 as the lower portion of the partition portion51 has a condensate drain hole 59, which is substantially in acircular-shape and opens at the target location, from which condensateis to be dropped. The target location, from which condensate is to bedropped, corresponds to the location at which the condensate drain hole59 is defined. The target location is substantially shifted by 90° fromthe bearings 5 along the circumferential direction of the innercircumferential periphery of the air cleaner hose 7. The targetlocation, from which condensate is to be dropped, may be at the hosewall surface and in the vicinity of the point directly above the warmwater heating unit, which hearts the throttle body 2, in particular, thecylinder portion 23, using warm water.

As described above, according to the present embodiment, the pocket 17(condensate passage 57) is defined between the hose wall surface of theair cleaner hose 7 and the partition portion 51. The pocket 17 extendsfrom the lowest point of the opening 13 of the PCV port 9 in the gravitydirection to the point shifted from the bearing 5 by substantially 90°in the direction of the inner circumferential periphery of the aircleaner hose 7. In the present structure, even when condensate flows outof or drips from the opening 13 of the PCV port 9, the condensate can bereleased to the location in the vicinity of the point, which is shiftedby 90° from the bearing 5 in the direction of the inner circumferentialperiphery of the air cleaner hose 7. In the present structure,condensate, which flows out of or drops from the opening 13 of the PCVport 9, can be released to the location in the vicinity of the point,which is shifted by 90° from the bearing 5 in the direction of the innercircumferential periphery of the air cleaner hose 7. As described above,the electronic throttle device 1 having the downdraft structureaccording to the present embodiment is capable of produce an effectsimilarly to the first embodiment.

Furthermore, the partition plate 53 of the partition portion 51 definesthe opposed portion 52, which surrounds and entirely blocks the opening13 of the PCV port 9. Therefore, condensate, which flows out of or dripsfrom the opening 13 of the PCV port 9, splashes in the horizontaldirection of the opening 13 of the PCV port 9 by being obstructed by theopposed portion 52. Even in the present condition, the condensate isobstructed by the side portions 55, 56 in the direction of thecircumference of the partition portion 51, and thereby accumulatedinside the pocket 17. In the present structure, condensate, which flowsout of or drips from the opening 13 of the PCV port 9, can be restrictedfrom scattering. Therefore, the throttle valve 3 and the shaft 4 can befurther protected from icing.

(Fifth Embodiment)

FIG. 13A shows multiple current plates provided in an air cleaner hose,and FIGS. 13B, C show an air cleaner hose, according to the presentfifth invention. In the electronic throttle device 1 having thedowndraft structure according to the present embodiment, the straightpipe portion 35 of the air cleaner hose 7 is airtightly joined with theupper end of the throttle body 2 in the gravity direction. That is, thestraight pipe portion 35 of the air cleaner hose 7 is airtightly joinedwith the upper portion of the throttle body 2 in the vertical direction.According to the present embodiment, the air cleaner hose 7 has themultiple current plates (current rectifying portion) 61. The currentplates 61 are, for example, integrally formed with the hose wall surfaceof the straight pipe portion 35 of the air cleaner hose 7. The currentplates 61 extend in the axial direction of the throttle bore 21, 22 andthe intake passage 11 in the throttle body 2 and the air cleaner hose 7.The multiple current plates 61 are substantially in parallel with eachother and arranged at substantially predetermined regular interval inthe direction of the inner circumferential periphery, i.e., hose wallsurface of the air cleaner hose 7. Each of the multiple current plates61 protrudes from the hose wall surface of the air cleaner hose 7 towardthe center axis of the intake passage 11 by a predetermined projectionlength.

In the present structure, the multiple current plates 61 are integrallyprovided in the hose wall surface of the straight pipe portion 35 of theair cleaner hose 7, and whereby flow of condensate can be regulated andrectified upstream of the throttle valve 3 in the intake passage 11.Therefore, airflow can be stabilized inside the air cleaner hose 7.Thus, turbulent flow and scattering of condensate can be restricted.Furthermore, flow of condensate can be controlled in the intake passage11 upstream of the throttle valve 3 inside the air cleaner hose 7.Therefore, condensate, which drips from the opening 13 of the PCV port9, the guide groove 14, the condensate drain groove 42, the through hole43, or the condensate drain hole 59, can be restricted from directlyfalling onto the bearing 5. In the present structure, the bearing 5 canbe protected from direct fall of condensate, and hence the throttlevalve 3 and the shaft 4 can be further protected from icing. Themultiple current plates 61 may be applied to the structure of each ofthe first to fourth embodiments.

(Sixth Embodiment)

FIGS. 14A, 14B show a bellows tube portion provided to an air cleanerhose according to the present sixth embodiment. In the electronicthrottle device 1 having the downdraft structure according to thepresent embodiment, the straight pipe portion 35 of the air cleaner hose7 is airtightly joined with the upper end of the throttle body 2 in thegravity direction. That is, the straight pipe portion 35 of the aircleaner hose 7 is airtightly joined with the upper portion of thethrottle body 2 in the vertical direction. In the air cleaner hose 7,the bend portion 33 and the straight pipe portion 35 therebetween havethe bellows tube portion (accordion portion) 34 including multiplebellows peak portions 62, for example. In the bellows tube portion 34,each of the multiple bellows peak portions 62 is inclined by apredetermined inclination angle with respect to the horizontal directionof the bellows tube portion 34. Each of the bellows peak portions 62 isinclined with respect to the horizontal direction of the bellows tubeportion 34 toward the target location from which condensate is aimed tobe dropped. In the present embodiment, the hose wall surface of thebellows tube portion 34 of the air cleaner hose 7 is dented toward theoutside of the bellows tube portion 34 so as to define condensatepassages (guide recessed portions, guide grooves) 63. Each of thecondensate passages 63 is inclined with respect to the horizontaldirection of the bellows tube portion 34 toward the target location fromwhich condensate is aimed to be dropped. The bellows peak portions 62,which are inclined, may be applied to the structure of each of the firstto fourth embodiments. In the present structure, flow of condensate canbe controlled in the bellows tube portion 34 inside the air cleaner hose7. That is, flow of condensate can be controlled in the intake passage11 upstream of the throttle valve 3. Therefore, condensate, which dripsfrom the opening 13 of the PCV port 9, the guide groove 14, thecondensate drain groove 42, the through hole 43, or the condensate drainhole 59, can be restricted from directly falling onto the bearing 5. Inthe present structure, the bearing 5 can be protected from direct fallof condensate, and hence the throttle valve 3 and the shaft 4 can befurther protected from icing.

(Modification)

In the above description, the throttle valve 3 according to the aboveembodiments is employed for controlling intake air supplied to thecombustion chamber of the internal combustion engine. Alternatively, thethrottle valve 3 according to the above embodiments may be used as anair intake flow control valve configured to generate swirl flow so as toenhance combustion of fuel-air mixture in the combustion chamber of theinternal combustion engine. Alternatively, the throttle valve 3according to the above embodiments may be used for a valve element of anintake passage control mechanism configured to open and dose an intakepassage of an internal combustion engine.

In the above embodiments, the electromotive actuator, which is providedwith the motor and the output power transmission mechanism, is employedas the actuator for actuating the shaft 4 of the throttle valve 3.Alternatively, a negative pressure controlled actuator, which isprovided with an electromagnetic negative-pressure regulator valve or anelectromotive negative-pressure regulator valve, may be employed as theactuator for actuating the shaft of the throttle valve.

The throttle valve 3 may be operated by mechanically transmittingdepression of the accelerator pedal to the shaft 4 of the throttle valve3 via a wire or the like.

The engine in the above embodiments may be a diesel engine. The engineis not limited to the multi-cylinder engine and may be a single-cylinderengine.

In the above embodiments, the guide groove (guide recessed portion) 14,which is dented toward the outside of the air cleaner hose (air hose) 7,is employed as the condensate passage (guide portion). Alternatively, aguide projected portion, which is projected inside the air hose, may beemployed as the guide portion.

Each of the opening 13 of the PCV port 9 shown in FIGS. 10A to 10C andthe through hole 41, 43 of the membranous member 15, 16 shown in FIGS.11A, 11B may be applied to the opening (PCV) of the fresh airintroduction passage (communication passage) 12 of the union pipe 6.

The above first to sixth embodiments may be arbitrary combined.Specifically, the guide groove (guide recessed portion) 14 in the firstembodiment, the direct connection between the bend portion 33 and thestraight pipe portion 35 in the second embodiment, the opening 13 andthe through hole 41, 43 of the membranous member 15, 16 in the thirdembodiment, the pocket 17 in the fourth embodiment, the multiple currentplates (current rectifying portion) 61 in the fifth embodiment, and thebellows peak portions 62 of the bellows tube portion 34 in the sixembodiment may be arbitrarily combined.

Various modifications and alternations may be diversely made to theabove embodiments without departing from the spirit of the presentinvention.

What is claimed is:
 1. An air intake apparatus for an internalcombustion engine, the air intake apparatus comprising: a housing havingan intake passage extending substantially in a vertical direction of avehicle, a valve configured to open and close the intake passage; ashaft supporting the valve; a bearing supporting the shaft; a hoseconnected with an upper side of the housing in the vertical directionand configured to lead intake air into the intake passage; and acommunication passage configured to communicate an inside of theinternal combustion engine with the hose, wherein the communicationpassage has an opening in the vicinity of a first point directly abovethe bearing, the opening has a lowest point in a gravity direction, andin a direction perpendicular to the gravity direction, the lowest pointis displaced from the vicinity of the first point directly above thebearing, so that in the gravity direction, the lowest point of theopening is prevented from coinciding with the first point directly abovethe bearing.
 2. The air intake apparatus according to claim 1, whereinthe opening is substantially in one of an ellipse shape, an oval shape,and a polygonal shape.
 3. The air intake apparatus according to claim 1,further comprising: a membranous member surrounding the opening, whereinthe membranous member has a through hole extending in a thicknessdirection through the membranous member, the through hole has a lowestpoint in the gravity direction, and in a direction perpendicular to thegravity direction, the lowest point is displaced from the vicinity ofthe first point directly above the bearing, so that in the gravitydirection, the lowest point of the opening is prevented from coincidingwith the first point directly above the bearing.
 4. The air intakeapparatus according to claim 3, wherein the membranous member has adrain groove, which protrudes downward in the gravity direction from thethrough hole.
 5. The air intake apparatus according to claim 1, whereinthe wall surface of the hose defines at least one current rectifyingportion, which extends substantially in an axial direction of the intakepassage.
 6. The air intake apparatus according to claim 5, wherein theat least one current rectifying portion includes a plurality of currentrectifying portions, which are arranged substantially in parallel atpredetermined distances along the wall surface.
 7. The air intakeapparatus according to claim 1, wherein the hose includes a bellows tubeportion having a plurality of bellows peak portions or a plurality ofbellows dip portions, which is inclined with respect to a horizontaldirection of the bellows tube portion by a predetermined inclinationangle.
 8. The air intake apparatus according to claim 7, wherein theplurality of bellows peak portions or the plurality of bellows dipportions is inclined toward the target location.